The present invention relates to bird feeders, and more particularly relates to improvements therein.
Selective bird feeders are well known in the art and are designed to limit the maximum size of a bird or animal which can access the seed in the feeder. The reasons for excluding certain birds may be many. Thus, as disclosed in U.S. Pat. No. 3,241,525, there is provided a selective bird feeder which is specific to cardinals. As taught by this patent, a favorite seed of cardinals is the sunflower seed; this seed is also popular with both smaller and larger birds.
Some larger birds will also access the seed and many such birds including crows, grackles, blue jays and the like are considered by some people to be undesirable.
A further problem associated with bird feeders is marauders which gain access to the seeds. In particular, squirrels are well known for their ability to reach the seed in a bird feeder and to devour the same. Many approaches have been tried to discourage or prevent squirrels from reaching the bird feeder, including various types of covers and baffles on poles. These seldom work as the squirrels have shown great ingenuity in overcoming such devices.
Some of the attempted solutions to the problem are disclosed in the prior art such as exemplified by U.S. Pat. No. 4,646,686 to Furlani which teaches a movable shroud. U.S. Pat. No. 3,145,690 to Bachman describes a bird feeder in which an inverted cylindrical hopper is suspended over a feeding pan; a bird perch surrounds the pan and is attached to a conical shroud. Both the perch and the shroud are supported by a compression spring whereby heavier birds or mammals on the perch cause the shroud to move downwardly.
Another shroud arrangement is shown in U.S. Pat. No. 3,126,870 wherein a cylindrical shroud surrounds a hopper and is mounted for rotation about a vertical axis under the bias of a weight.
While all of the above references disclose shroud type arrangements, such devices have not appeared to have received commercial acceptance in the marketplace. It might be surmised that this is due to the fact that some of the arrangements are relatively complicated and/or expensive to produce.
It is an object of the present invention to provide an adjustably selective bird feeder having a movable shroud to protect and isolate the access openings by which the birds can gain access to the feed in the container from unwanted intruders.
It is a further object of the present invention to provide an adjustably selective bird feeder which uses a compressible member such as a spring to cause the shroud to move and protect the access openings when predetermined weight is placed thereon.
It is a further object of the present invention to provide a feed container for a bird feeder which is easy to manufacture and uses a minimum of components.
It is a further object of the present invention to provide a bird feeder which can be easily disassembled without the use of tools to provide for easy repair and easy access for cleaning.
According to one aspect of the present invention, a bird feeder comprising a feed container having a base and an outer wall extending upwardly therefrom, at least one feed container access opening in the outer wall, a cover member, the cover member being removably connected to an upper portion of the feed container, a shroud extending about at least a portion of the feed container, at least one shroud access opening substantially aligned with the feed container access opening to thereby permit access to the feed container, an elongated hollow center tube within the feed container, the hollow center tube being connected to the feed container, an elongated rod within the center tube, the rod being connected to the shroud at a lower end of the rod, the rod being movable within the center tube axially, and biasing means associated with the rod at an upper end thereof, the biasing means biasing the rod and the shroud to a position wherein the feed container access opening and the shroud access opening are substantially aligned while permitting the shroud access opening to move out of alignment with the feed container access opening when a predetermined weight is placed on the shroud.
In a greater detail, the bird feeder of the present invention is designed as a multi component device which can be easily assembled and disassembled without the use of tools. Furthermore, the components of the feeder, when disassembled, can be placed in a cleaning device such as a dishwasher to sanitize all the components and thus prevent the spread of disease which is a frequent problem associated with bird feed which remains in the container for a substantial period of time.
The bird feeder of the present invention can be sized to meet the requirements of the industry. Thus, the feed container, which is preferably formed of a transparent plastic material, can be sized to accept the desired amount of bird feed. Preferably, it is made of a material which will resist the attack of marauders such as squirrels and to this end, a plastic material such as Lexan(copyright) may be utilized.
The components of the bird feeder which might be subject to attack by the marauders such as squirrels can be made of an appropriate metallic material such as aluminum. Thus, the cover and the shroud would most desirably be made of such a metallic material.